semiquantitativ

Semiquantitativ (semiquantitative) refers to measurement approaches that estimate, rather than determine with exact precision, the amount of a substance. In semiquantitative assessments, results are often expressed as categories, ranges, or relative scales (for example, negative, trace, low, medium, high; or 0–3+), or by comparison to reference standards. The aim is to convey information about order of magnitude or relative abundance without reporting a specific concentration, unless a separate calibration is applied.

Semiquantitative methods are widely used when rapid screening, simplicity, or limited resources are factors. Common examples include colorimetric test strips in chemistry, semiquantitative culture methods in microbiology that estimate microbial load by serial dilutions, and immunoassays in clinical diagnostics where the intensity of a signal is categorized. In pathology and molecular biology, semiquantitative scoring systems are also common, such as immunohistochemistry scoring (for example 0, 1+, 2+, 3+) to indicate expression levels of a target protein or marker.

Limitations of semiquantitative data include subjectivity, a restricted dynamic range, and dependence on sample quality and experimental conditions. Semiquantitative approaches are often used for initial screening, triage, or prioritization, with quantitative methods pursued when precise measurements are required. To improve reliability and comparability, standardized scales, calibration, and consistent procedures are important.